A sputtering method has been widely used to produce recording media such as hard disks and optical discs.
However, a target used in a film deposition step during sputtering is only used at an amount of about 40 to 60% at most of its total mass according to the principles of the film deposition method.
Therefore, recycling of a spent target has been desired. This recycling is achieved, for example, by a wet process in which a metal is separated and recovered for each constituent element after being melted by an acid and the like. As another exemplary method of the recycling, a spent target may be subjected to a refinement process of a metal that constitutes the target. However, these methods of recovery entail high cost, and are uneconomical.
On the other hand, Patent Literature 1 describes a technique to produce a regenerated target by using an HIP method after filling an eroded groove of a spent target with a new raw material powder for a target.
Also, Patent Literatures 2 and 3 describe a technique to produce a regenerated target by using an HIP method after covering not only an eroded groove of the spent target but also the regions except the eroded groove with a raw material powder for a target having the same composition as the spent target.
However, the HIP method is required to use an HIP apparatus which results in high cost.
On the other hand, Patent Literature 4 describes a technique to produce a regenerated target by using a hot-pressing method with uniaxial pressing instead of the HIP method. Specifically, it describes a technique to carry out hot-pressing with a new raw material powder for a target being placed on an erosion part side of the spent target.